Electrical apparatus



' oct. 4, 1 932. A

C. A. JACKSON ELECTRICAL v APPARATUS s sheets-snaai 1 Filed' lay 28 1 927 .IN RQ. Y lE m@ Wm CA.. 0 EA VJ n wf., A .Af s w lm L mf H C B ocr. 4, 1932. A Y c. A'. Mckson 1,880,203

Y .ELECTRICAL APPARATUS Y Findlay 28. 1927 s sheets-sheetJ 2 1o le INVENTOR CHARLa AJJACK om E ATTO NEY 0ct.4,1932. c, A. JACKSQN 1,380,203

ELECTRIAUAPPARATUs Filed nay 28, .1927 5 sheets-sheet s \/o 13e rp across control d w e hcCavd'rd v To al Vous Patented oa. 4, 1932 PATENToFFlcE GIALLE A. JACKSON', 0f BIDGEWOOD, NEW

mBICAL 'Application iled lay 88,

This invention relates generally to electrical power generating equipment and more particularly to improvements in both the electric generator and the driving means' 5 therefor. w y The power unit s cically considered in 1 this application, which is a continuation in art of my co-pending applications, Serial Y o. 135,756, tiled September 16, 1926, and Selo rial No. 152,136, tiled December 2, 1926, is

not only particularly adapted for automatically supplyingcurrert in theatres, hospitals and the like, in case of an emergency, such l as when the main city current fails, but due l5- to an improved combination of elements in the generator the latter is rendered available for purposes where a relatively constant voltge is desired under varying operating conitions.l l

20 One object of my invention is provide an improved generator adapted to maintain a.l snltantially constant` vol during speed iluctuations. [A morespec' c object in this respect is'to provide an improved'combina- 25 tion of elements including the generator iield andmeans for automatically controlling the current therein, thereby to effect substantially constant voltage. A further object is to have an automatic thermal control oper- 3 atedl bythe generator current and so arranged inthe improved combination as to maintain voltage regulation during speed fluctuations.

Other objects are; to provide ,anA improved 35 arrangement of controlling element for the generated current and the generator driving. mechanism which is'specifically shown in this application to be a hydraulic turbine, although it will of course .be `I inderslooqd that other-driving means may be usedsuch as steam turbines or the like; to provide an improved arra ment whereby a valve for controlling turbineactuating fluid may be ad` justed through a wide range without affecting operation of a switch which controls .the

arrm'rus 1m. sulla no. 195,038.

generator current; to provide an improvedcombination of elements including a quickthrow switch and operating means therefor and to provide an improved arrangement for conducting luid ilow to and from the hy- 50 draulic turbine.

Other .objects and advantages will be seen from the following description of the accompanying drawings, in which:

' Fig-1 is a vertical sectional view through 55 ghe prime mover and controllm' g means there- Fig. 2is a side elevation of the prime mover and generator,

Fig. '3 is a generator diagram inno cluding my thermal control,

Fig. 4 is a partial sectional elevation of the adjustahie resistance shown in the diagram .ofF ig. 5,

lFigis awiring'diagram ofa further oliv modified arrangement including the automatically adjustable resistance element,

Figs. 6 and 6a are graphs showing respectively without and with variable field control the relation between the generator volt- 'l0 age R. P. M., and the load,

Fig. Y is a graph showing the Arelation between the current and ristance of -the thermal control, and

Fig. 8 is a diagram of the emergency and 75 main supply circuits and showing diagramlmatically the switch and relation of other parts.

In small electrical generator units, where it is necessary to a relatively constant voltage during speed and load uctuations, it is dirable to provide a voltage lating arrangement which is not only' cient but is 'also simple and inexpensive in construction,l maintenance and operation. Due to the relatively'low cost of a small unit, elaborate and expensive', speed controlling-or governing devices are not warranted as in large units. My arran tnt, however,`by doing entirely away with speed governing mechanism, is particularly adaptedfor small units, whether the generator be driven by a hydraulic or steam turbine. However, in any typefof small fluid operated unit, and posslbly other types, due to the' small capacity thereof and its relative sensitiveness to speed fluctuations caused either by load variations or fluctuations in power supply, it is most desirable to have an efficient control. Various arrangements have heretofore been proposed 'in an attempt to meet certain ofthe above conditions. Such prior devices have included, for instance, magnetic drags or dampers to prevent overspeeding of the generator, re-

1sistance chokesin the main circuit and the use of a field for bucking the normal generator field when. normal conditions exist. While these arrangements may accomplish results toa certain extent, the results are not 2 obtained as Iefhciently, simply or effectively as in my arrangement. y

In my directcurrent generator G 'as shown in Fig. 3. lI employ a shunt field Sh and a series field Se. By making the `series field constitute the major field strength, possibly 75% of the total, and by using the type ,of generator I have -shown in combinati-on with 'an uncontrolled hydraulic turbine, it is posrsible to effect a substantially constant voltage 8 during load and speed fluctuations; This resvlt is possible, as is shown in my co-pending applications, due to the turbine speed being practically inversely proportional to its load. Hence there is a peculiar combination of cooperating operating characteristics between a hydraulic turbine and a generator of the type herein disclosed.

In order to obtain closer voltage regulation in the arrangement just described, and to obtain such regulation with an extremely simple and efficient means, I propose the further use of a thermal regulating member Ite lwhich I place across the series field Se.'

'rThis thermal control which is self-contained both as to operation and construction consists .preferably of aseries ofwires Y, made df iron or those alloys having characteristics similar to iron, one example being nickel steel. Q These wires are connected in parallel and constitute a unit connected by wires A and B across the series field thereby to control bypassing of current around the series field. Instead of several wires Y, a single wire could be used of suitable sizeand in any case the wires would, be suitably enclosed in a convtainer adapted to exclude rair from the wires. A characteristic of these 'controlwires, -which f lends itself particularly for cooperation with my field arrangement, is that with an increase of current through the wires the-latter. be-

` come heated and the resistance thereof automatically increases. ,This relation exists through suclra relatively wide current range l.that when the load increases and 'the speed ofthe generator decreases. the resistance of the wires automaticallyv increases, thereby forcin more current to pass through the series eld. This results in increased voltage, even thoughthe generator speed may have fallen. Conversely, when the load drops the thermal 'control wires or resistance Re will cool and in doing so their resistance drops thereby permitting a greater amount of current to be by-passed around the series field through wires A-B, resulting in a reduced field current. This reduced field current, however, does not lower the generator voltage, because as the load decreases the generator speed increases and maintains the voltage V'constant with the smaller field current.

If it is desired to obtain even closer voltage regulation than that just described, a thermal control Rh may be placed in series with the shunt field. In operation, as the load is decreased the generator speed increases with the result that'the voltage impressed across the shunt field is increased. An increase of voltage would cause a greater amount of current to flow through the thermal control Rh resulting in the wires thereof becoming heated and offering more resistance thereby holding back current flow through the shunt field. This \reduces the field strength of the shunt field and thus tends to effect reduction ofthe generator voltage. Therefore, an increase of generator speed will not produce a proportionate increase of voltage by the shunt field, as would bethe case without the thermal control Rh, the resistance of which automatically rises and falls in accordance with the impressed voltage or, in equivalent terms, with thespeed of the generator.

Conversely, when the load increases and the generator speed decreases, the impressed voltage across the shunt field Sh decreases, resulting in the thermal control Rh lowering in temperature and likewise resistance, thereby permitting more.current to flow through the sh'unt field. Increase of the shunt field current tends to proportionately increase the generator voltage, thus helping to maintain the same constant, even though the generator speed drops. Thus, when the two resistance 'elements Re and Rh are employed voltage reg- 4/ulation is made doubly effective.

-From the foregoing it is seen that irrespective of the use of control Ri, the combination of the series field Se and'control Re are oper- *ative in accordance with variations in speed and load to maintain a relatively constant voltage. Also irrespective ofthe use of control Re the combination' of the shunt field Sh and control Rhp are, operative in accordance with variations in speed, therebyto mainticularly adapted for variable speed shunt field and its control alone is more par- 'units such as locomotive head light generator units wherein a variable .power supply of actuating fluid must .be contended'with. -In most instances, if no t all', both the series and shunt iields will-be used together, although the use.

or non-use of their respective thermal con-.- trol will depend upon the field of service just explained. v 1

f it is desired to have the automatic controls Re and R-kof relatively small capacity,

' supplemental manually adjustable rheostats r may be inserted in series with the respective controls. These rheostats can be adjusted for a rough approximation of the voltage desired, thereby leaving the automatic controls to take f4care of the finer adjustments to obtain the necessary substantially constant'voltage. In case of the thermal control Rh the wires thereof will be so proportioned that during normal opera'on it will offer anamount of resistance (or voltage drop across the control) intermediate its high and low points on the curve shown in Fig. 7, thereby permitting a wide range of control either above or below normal voltage.

A wiring diagram and switch arrangement preferably used is diagrammatically shown in Fig.`8, wherein city current is supplied through'main 'supply' lines 45-and 46 across which is disposed the automatic starting s olenoid 40. The wire is connected to the stationary switch element 4@fit1-iis inturn being adapted for connection tothe other switch element 48 by 'switch arms '49. Switch element 48 is in turn connected byawire 50 to'a stay tionary ele'ment'51 of'ag'secon'd switch, element 51 infturn being -connected .to the main line 46 as by wires 52,53 land 54. The exit lights 55, in case such lights are used as in theatres, etc., willbe connected across wires also emergency lights 56. The second-.switch has arms 57 adapted to connect element 51 with a similar element 58, f

it being noted-'that' the' arms 57 and 49 `are angularly disposli, and diagrammatically shown as pivotally mounted upon separate vshafts which are insulated as at 59.

A wire 60`leads from one side of the genera-V tor to switch element 58, while' the wire 54 continues on around to the otherside of the generator. In order to permit operation of the emergency lights independently of the lswitch30, there'is provided a wireA 61 and The quick-throw'felatureof the switch 30 may be accomplished with any standard type of quick-throw mechanism, but asthe specific feature of such a device does not per se constitute, azpart -of my invention, the details thereof have not been shown. l The driving-means, which is herein shown as a hydraulic impulse turbine but 'which could be 'of the reaction type such as shown my co-pending application or could bc a steam turbine, comprises a suitable structure 1 for housing and support' a standard type of impulse wheel 2, which 1s mounted upon a shaft 3 preferably directly connected to the generator G. Actuating-luid, as is usual, is supplied through an inlet pipe 5 and nozzle 6, which is controlled by a suitable needle 7. In some installations it is desirable to permit discharge water to be conducted away either in the direction of the inlet or opposite thereto, and to accomplish this the outlet- 8 is made reversible merely' by removing bolts 9, turning the outlet and then reinserting the bolts.

The control for the unit here shown is particularly adapted for. emergency purposes, such as in hospitals, theatres and the like, this phase of the operation being more fully described in my application SerialfNo. 152,;

136, filed December 2, 1926, although the presply of current. ,The controlling elements consist briefly of a stem 7 extending rearwardly through a suitably packed gland and being pivotally connected as at 9 to an operating lever l0, the lower en d of which is pivotally connected to a link 1 1, in turn pivotally connected to a normally stationary but adjustable element 12. A compression spring )13 is interposed between a packing gland 14 and an adjustable nut 15, which is threadedly connected tothe rod 7 thereby always main-- taining a constant force on the-.rod 7 in a direction for opening the needle valve. To hold the needle valve in closed positionfa latch bar 16 is pivotally connected as at 17 to the lever 10, while its other end is constantly urged upwardly bya flat spring 18,V which is secured to the stationary casing 19.r A pin and slot 'arrangement 20,guides the free 'end of the latch bar 16 and said bar is projecting outwardly from the casing v19 on each side of the latch bar. A collar 26 is secured to the latch bar and when in its outer position abuts member' 24.A .Adjustment ofY member 24 is affected by n uts 27 disposed on each side of abutment 24 and threadedon the studs 25.

vTo permitthe emergency generator currentand the city current to be distributed over the same wires in the hospital, theatre or the like, the switch mechanism 30 is provided, whereby when the emergency generator current is available the same is connected to the' distributing wires and thecity circuit is disconnected and vice versa. To accomplish this in an efcient manner, and to permit adjustment of the needle valve 7,1 I have provided the following arrangement `in distinction to the one described in my co-pending appliation, Serial No. 152,136. Herein, the switch 3() is of 'the quickthrow type, having a pivoted, forked operating arm 31. The inner surface of each fork is adapted for engagement by a pin 32, which is carried upon a rod 33 slidably mounted in asuitable bearing 34, this-bearing having a slot 35 to receive thepin. The length of 'the'bearing' slot permits considerable outward movement of the rod and pin 32, as shown by dotted lines in Fig. 1.

By this arrangement, it is possible to effect considerable adjustment of the needle valve through the nuts 27'withoutin any way afvfecting either the extent or quickness of operation ofthe switch.

To release latch bar 16 a solenoid 40 is connected in series with the city circuit and the solenoid core'carries a hammer 41 adapted to fallv and strike the latch bar 16 when the city circuit fails, thereby'depressing -spring 18 and the latch bar to disengage latch members 22,23. Spring 13 thenA forces needle valve 7 open and the water wheel starts up and curlrent is generated, the city .supply means be.

ing simultaneously disconnected from, Whilev 'the generator current is connected to, the distributing wires.

In the modified arrangement of controlling the series field in accordance with the generator load, there is provided as shown in Fig.

' core 68. An-oil dashpot 69 has a ported-pis- I 76 through an adjustable set screw 77 ce i La solenoid 50. This device comprises cur rent and voltage coils 66 and 67 respectively, within which is disposed a suitable solenoid ton 70 connected to the lower end of 'the core while the'upper end thereof is connected to a lever 71 normally pulled downwardly an ad]ustable tension spring 72. The other end of lever .71is pivotally :supported upon a bracket72, which carries any suitable' variable resistance, herein disclosed preferably' as 74 and 75, while"v variable resistance is obtained by varying pressure upon af plunger by the lever 71.' l

In Fig. 5 'this supplementary field-control .is diagrammatically shown in the wiriu g d iaam. -As shown the generator G has a usual shunt field adapted if desired ltobe controlled by a manually operated rheostat 8l, while a series field v82 vis vdisposed as usual in voneiftlie main lines 83.E The other main line a carbon pack ,7 3, the termin als of which are.

carried 84 passes by' way 'of line. 85 to thecurrent coil 66 of the solenoid 50 and out through a continuation of the mainline 84. The voltagel coil 67 is connected across lines 83 and 84 by wires 87 and 88,'while the field resistance carbon pack 73 is connected across the terminals of the series field 82 by wires 89 and 90. As-

suming that the desired shunt field regulation is obtained for any given seasonal load', when -the turbine speed increases or drops the current and voltage coils 66 and 67 will operate through solenoid core 68, lever. 71 andplunger 76 to vary the'resistance 73 and va-riably control the current low through the serieseld 82, thereby to maintain a voltage regulation which is very close and fully comparable to that voltage regulation obtained by 'the speed governed turbine units.

The degree of voltage regulation obtained lby any of myimproved combinations is diagrammaticallyjshown in Fig. 6 andv Fig. 6a. As shown in Fig. 6a for wide-turbine speed variations the',voltage is a substantially straight line. While thefline is shown as" slightly increasing as the load lncreases,

' which is desirable, it may by properly proportioning either the resistaince 81 or the shunt` series field coils be made to take any desired inclination. In the form o control shownin IFig. 4, the dashpot69 insures smooth operation of the resistance 73, thereby preventing anysudden changes of the series field. The

degree of greatest 'resistance of the carbon pack 73 may be adjusted by a set screw 92.

IeIaim: 1. The combination 1n a power .generating apparatus including a prime moyer having means which is .invariable during operation for conducting flow o f power 'medium thereto, al generator driven by said prime mover, means for creating a total effective field flux including afield circuit adapted' upon variations of current thereinV to vary, inthe same direction, the total effective field flux, and

thermalmeanfs arranged with respect to saidfield circuit soas to control current therethrough automatically in accordance with the generator load which is coordinated in a predetermined manner with turbine speed which increases'with decreased load and vice versa.

2. The combination in a power generating apparatus including a prime mover having means which is invariable during operation .for conducting flow-of power medium thereto,

means which is invarable duriendg operation for conducting flow of power m um thereto, a generator driven by said prime mover, a field circuit, a self-contained thermal operated resistance, means connected thereto whereby the field current is varied automatically in ac-, cordance with and in a direction opposite to the variations in the generator speed.-

4. The combnation in a power generating im apparatus including a rime mover having means which is invaria le during operation for conducting iow of power medium thereto, a generator driven by said prime mover, a series field circuit, and means including controlling means connected in a circuit parallel with Isaid series circuit whereby during an in-A crease of load current and decrease of enerator speed the current through said iie'ld 'and parallel circuits are automatically relatively adjustedand a field strength created to maintain a substantially constant voltage.

5. The combination in a power generating apparatus including a' prime mover having means which` invariable during operation for conducting `flow of power medium thereto,l

a generator driven b said prime mover, a -series field circuit, an means, including controlling means connected in a circuit parallel with said series field, whereby during increase f $0 of load current andl decrease of generator speed the current through said field andparallel circuits are automatically relatively adjusted and a field strengthcreated suiiicient 4 to maintain a substantially constant voltage,

i saidcontrolling means being adapted upon La. decreased load and increased generator speed to by-pass automatically a greater amount of current around the series ,field thereby to maintain a substantially constant 40 voltage.

i 6. The combination in a power generating apparatus, comprising a hydraulic turbine having a substantially fixed flow area during loadand speed variations, a generator driven 4`5 thereby havin a series field, and meansK disposed in para el with skaid series field for controlling the current therethrough automati- Jcally in accordance with load and speed fluctuat-ios thereby to maintain a substantially y constant voltage, said means comprising an load and speed variations, a generatordriven thereby having a shunt iield, and means associated withsaid shunt field for controlling the current therethrough automatically in accordance with speed iiuctuations, thereby having a-substantially fixed flow area during f tending to maintain a substantially constant v voltage, said controlling means comprising an' electrically-heated element adapted to have its resistance vary in accordance with the current passed therethrough.

9. The combination in aypower generating apparatus comprising a hydraulic turbine having a substantially fixed flow area during load' and speed variations, a generator driven thereby having shunt and series fields, means for` controlling the current to said fields automatically in accordance with load and speed fluctuations, thereby tending to maintain a substantially constant voltage.

' 10. Thev combination in a power generating' apparatus comprising a hydraulic turbine having a substantially fixed flow area during load and speed variations, a generator driven thereby having shunt and series fields, means for controlling the current to'said el-ds automatically in accordance with load and speed riuctuations, thereby tending to maintain a substantially constant voltage, said controlling means comprising an element the resistance or which automatically varies in a'ccordance with the current passed therethrough.

11. Thecombination in a power generating apparatus comprising a hydraulic turbine having a substantially fixed flow area during `load and speed variations, a generator driven thereby having shunt and series iields, means for controlling the current to 'said fields automatically in accordance with load and speed iuctuations, thereby tending to maintain a substantially constant voltage, said means Vcomprising elements the resistance of which varies automatically in accordance with the current passed therethrough.

12. The combination in a power generating apparatus comprising a hydraulic turbine having a substantially iixed How area during load and speed Variations, a generatordriven thereby having shunt and series fields, the latter of which produces approximately 75% of the eective iield iiuX, and means disposed in parall l with said series field for controlling the current therethrough automatically in accordance'with load and speed fluctuations thereby to maintain a sub stantially constant voltage, said-means com- 4prising an electrically heated element the temperatureand resistance of which varies inaaccordancewith the current passed therethrough.

13. The combination in a power generating apparatus .including a prime mover having Ymeans which is invariable during operation for conducting How of power medium thereto, a. generator driven by seid rimemover, shunt and series fields varrange for accumulative action and means including a thermal resista-nce unit, variably'heated by the current passing therethrough, for varying the' total field flux automatically in accordance with variations in the supply of current to said thermal means.

CHARLES A. ACKSON'.v 

